Some Problems Research On Power Supervisory Control And Data Acquisition

A growing number of remote monitoring is applied in electricity systems and other industrial fields.With the development of the national economy as well as people's material and spiritual living standards,the need for automation is on the rise. However,for the restrictions of communication channels and the discordance of communication protocols,the customers have a higher requirement for the communication quality and reliability of remote monitoring.Therefore,remote monitoring system is of great significance to improve the reliability of electricity supply,expand power supply capacity and reduce line losses as well as decrease labor intensity.Considering the practical need for remote monitoring and the desire to lower the cost of communication,as well as the demand to dispose simplified communication and the broad market demand,we conducted our research and study on remote monitoring system.First,this article has deducted a summary to the development of our country's Power Supervising and Control System.Also it made an analysis to the typical transformer substation automated systems overseas as well as the present situation of both the application of the automated system communication network of transformer substation and the application of communication protocols.The key matters of the remote monitoring system have also been taken into in-depth consideration,including the long-distance communication channels,the communication protocols and the backstage monitoring platform.Based on that,we proposed the power distribution supervisory system that based on the.NET platform and long-distance dispatching system based on the WEB server.On the foundation of the realization of this system, we offered different designing method for different communication channels in view of different geography situations,which has been proved useful and effective by the massive practical applications.The main contributions of this article include: 1.The article carried out a research on the fundamental theory of Remote Terminate Unit(RTU).We developed and designed several different types of RUT, and made the electrical network's access a reality.2.The article studied the commonly used long-distance communication channels, and offered the methods for choosing from them according to practical situation.The article also conducted a research on the communication protocols.Grasping of different kinds of inter-stations communication protocol and long-distance communication protocol,we has designed the brand-new communication repeater for long-distance communication under particular circumstance.The article also proposed Polling terms based on CDT agreement and designed the data relaying based on the GPRS,therefore overcame the harsh request that is point-to-point communication, according to the CDT agreement.3.The article conducted a research on the function of the long-distance monitoring backstage.Regarding to software's development environment,we completely adopted the most popular.NET platform,as for the developing language, we employed the most advanced C# language,SQL Server 2000 database,.we has developed the supervisory system based on three-layer construction backstage, therefore has completed the entire long-distance monitoring work.4.At last,this article made a systematic conclusion to the completed work and research results obtained,pointed out the questions stand for further study and research later.This article is arranged as follows:The first chapter:Introduction.We made a assay of the development profile of the transformer substation automated system and the application of the power transformation inter-stations insulation communication protocols,meanwhile,the background and resources of the research work of this article are also given in this chapter.The second chapter:The function and design of RTU.This chapter first proposed the idea of RTU with on-site function,then carried out a research on alternating sampling algorithm,and applied the algorithm in the projects.What's more,we improved the measuring technique using frequency tracking,and therefore the equipment can turned on the main dispatching electricity system reliably.The third chapter:Study on remote communication system.In this chapter,we first established the communication system model,and then conducted an investigation on data communication principle,communication ways,the communication channel and the optimized choice as well as the communication protocol analysis,therefore,the key problem of wireless communication and communication repeater of GPRS.The fourth chapter:We made a study on circulating protocol and interrogatory protocol,meanwhile made an approach to the IEC61850 agreement.Then we proposed the idea of polling agreement based on CDT data format,which has obtained successful application in the actual item design.The fifth chapter:Research on interval layer communication.Taking the hypopiesia remote control as background,in this chapter,we suggested multiplexing with CDT channel,expanding the CDT agreement,and making remote control of PLC by using serial communication,hence we can replace the trapezoidal pattern of PLC.The sixth chapter:According to the supervisory system's request,we offered systematic functional module system,proposed the new module frame of backstage monitoring software.In the article we first proposed systematic design's hierarchical structure and the software modulation division,then we adopted the most popular.NET platform,the most advanced C# language as developing language,the VC6.0 two platform mix development pattern,SQL Server 2000 database.Based on all the above resources we has developed the backstage supervisory system based on three-layer structure,therefore completed the entire long-distance monitoring work.The seventh chapter:Conclusion and prospect.In the last part,we made a conclusion about all the research work mentioned above,in the end,we raised the part which stands for further investigation.